1. Field of the Invention
The present invention relates to a ventilator which has a soundproof construction which reduces the amount of noise propagated into a room, which noise is generated by an air blower or the like.
2. Description of the Related Art
In recent years, there has been much demand for a ventilator having an air blower incorporated therein because it creates a pleasant indoor environment. Therefore, it has been desired that noise generated by the air blower in the ventilator be as low as possible. Under these circumstances, a ventilator has been hitherto constructed as disclosed in, for example, Japanese Utility Model Laid-Open. No. 55-61253.
The construction of the conventional ventilator will be explained below with reference to FIG. 5.
As shown in FIG. 5, the main body 101 of the ventilator incorporates therein an air blower 104 having a ventilation casing 103 provided with a fan intake opening 102, an intake opening 105 being provided on the bottom side of the main body, which side the fan intake opening 102 faces. Plate-like sound absorbing members 107 having a great number of ventilation holes 106 are provided in the entire surface of the intake opening 105 of the main body.
With the construction described above, noise generated by the air blower 104 is absorbed by the sound absorbing members 107, and the propagation of the noise into a room is reduced.
In such a conventional ventilator, as the plate-like sound absorbing members 107 having the great number of ventilation holes 106 are provided over the entire surface of the intake opening 105 of the main body, the sizes of the sound absorbing members 107 must be made quite large to increase the sound absorbing effect. As a result, the respective sizes of the openings of the ventilation holes 106 must be decreased, thus causing problems, namely, ventilation resistance being increased and ventilation efficiency being decreased.